 They initially numbered around 24–29,000, but some 4,000 received amnesty and returned to the Soviet Union and many others were expelled under Aleksandar Stamboliyski.With Bulgaria becoming part of the Eastern bloc following World War II, a number of Russians emigrated to the country.Today, foreign (including Russian) businessmen living in Bulgaria are eligible for Bulgarian passport under specific conditions (such as investing over $250,000 or running a business, and having a clean slate).